The present invention relates generally to assemblies for interconnecting or otherwise terminating optical fibers, and, more particularly, to receptacles for receiving corresponding fiber optic plugs.
Optical fibers are used in an increasing number and variety of applications, such as a wide variety of telecommunications and data transmission applications. As a result, fiber optic networks must include an ever increasing number of enclosures in which one or more of the optical fibers are interconnected or otherwise terminated. For example, fiber optic networks, such as cable television (CATV) networks, may include a number of optical network units (ONUs) in which the optical signals propagating along the optical fibers are converted to respective electrical signals. In addition, telephone and CATV networks can include a number of network interface devices (NIDs); each NID is associated with a particular subscriber. Upon receiving the incoming optical signals, the NID splits and routes the signals to predetermined locations, such as to various telephone or CATV outlets. Like an ONU, the NID can also convert the incoming optical signals to electrical signals, if necessary. Fiber optic networks can also include a number of other closures, including splice closures, in which various ones of the optical fibers are spliced or optically connected. Regardless of the type, these enclosures provide protection, such as from moisture or other forms of environmental degradation, for the optical fibers and, more particularly, the point at which the optical fibers are spliced or are otherwise optically connected.
These enclosures, such as ONUs, NIDs, and other closures, typically include one or more receptacles in which the individual optical fibers of a fiber optic cable are connected to respective optical fibers within the enclosure. The optical fibers within the enclosure can then be interconnected or otherwise terminated as desired. Conventionally, receptacles have included a receptacle housing defining an internal cavity and an adapter sleeve disposed in a fixed position within the internal cavity defined by the receptacle housing. The adapter sleeve is designed to receive a pair of ferrules, each of which is mounted upon the end portions of a plurality of optical fibers. One of the ferrules is attached to the end of optical fibers extending from a cable, ribbon, or optical fiber device that extends into or is located in the interior of the enclosure to facilitate splicing or other interconnection or termination of the optical fibers. As described below, the other ferrule is mounted upon optical fibers extending from a cable, ribbon, or optical fiber device that extends outside or is located outside of the enclosure, such as the optical fibers of a fiber optic cable. The adapter sleeve assents in gross alignment of the ferrules, and ferrule guide pins or other alignment means assent in detailed alignment of the optical fibers mounted on the end faces of each ferrule.
In order to mate with the receptacle of a conventional enclosure, a fiber optic plug is mounted upon the end portion of a fiber optic cable. Typically, the plug includes a generally cylindrical plug body and a fiber optic connector including a plug ferrule disposed within the cylindrical plug body. In order to protect the plug ferrule, the cylindrical plug body may partially or completely surround the lateral sides of the fiber optic connector. While the end of the cylindrical plug body is open such that the ferrule is accessible, the end of the cylindrical plug body does extend slightly beyond the ferrule to provide further protection. The ferrule is mounted upon a plurality of optical fibers of the fiber optic cable such that mating of the plug and the receptacle will align or connect the optical fibers of the fiber optic cable with respective optical fibers within the enclosure.
In the process of mating the plug and the receptacle, the plug ferrule is inserted into one end of the adapter sleeve of the receptacle. The adapter sleeve therefore aligns the plug ferrule with a receptacle ferrule that is attached to the end portions of optical fibers from a cable, ribbon, or optical fiber device that extends into or is located in the interior of the enclosure. As a result of the construction of a conventional fiber optic plug, one end of the adapter sleeve is received within the open end of the plug body as the plug ferrule is inserted into the adapter sleeve. In addition, in order to retain the plug ferrule within the adapter sleeve, the fiber optic connector of the fiber optic plug and the adapter sleeve are designed to be mechanically coupled, such as by means of a pair of latches. While the latches effectively couple the plug ferrule and the adapter sleeve, the mechanical coupling of the fiber optic connector and the adapter sleeve disadvantageously limit float between the plug ferrule and the adapter sleeve.
Several different types of conventional fiber optic connectors have been developed. Examples of some well-known connectors include an MTP connector, an MTRJ connector, an SC-DC connector, a Unicam(trademark) connector, an SC connector, a DC connector, and an LC connector. The size, shape, and latching mechanism of each of these conventional connectors are somewhat different. Correspondingly, the size and shape of the adapter sleeve of the fiber optic receptacle designed to receive a fiber optic connector, including the above-mentioned different types of conventional connectors, are also different. As such, according to conventional practice, different fiber optic receptacles are generally utilized in conjunction with the different types of fiber optic connectors. In this regard, the fiber optic receptacles generally define differently sized internal cavities corresponding to the sizes of the adapter sleeve and, in turn, according to a ferrule of the fiber optic connector to be inserted within the adapter sleeve. Accordingly, a technician typically has to maintain several different types of fiber optic receptacles in inventory so that the proper type of fiber optic receptacle can be installed depending upon the type of fiber optic connector to be inserted into the receptacle. As will be apparent, maintaining a number of different types of fiber optic receptacles in inventory is not only somewhat cumbersome for the technician, but also increases the overall costs associated with the inventory.
An improved fiber optic receptacle is therefore provided according to this invention that addresses many of the shortcomings of conventional fiber optic receptacles. In one embodiment of this invention, the fiber optic receptacle includes an adapter sleeve for receiving and aligning a plurality of connector types wherein the adapter sleeve defines a lengthwise longitudinally extending passageway through opposed first and second ends, a receptacle housing comprising an interior surface and an exterior surface, and a bias member disposed within the receptacle housing. The adapter sleeve has a first end that is adapted to receive a plug ferrule of a fiber optic connector contained or partially contained within a fiber optic plug and a second end is adapted to receive a receptacle ferrule from a second fiber optic connector, optical device, or the like. Further, the receptacle housing includes opposed first end and second end, wherein the first end of the receptacle housing is adapted to receive the adapter sleeve and wherein the second end of the receptacle housing is adapted to receive the receptacle ferrule. Still further, the bias member operably engages the adapter sleeve so as to urge the adapter sleeve towards the first end of the receptacle housing, and, thereby the bias member is configured to floatingly align the plug ferrule with the receptacle ferrule engaged in the adapter sleeve.
Typically, the receptacle provides access to an enclosure or the like such that optical fibers extending from a fiber optic cable may be aligned with and optically interconnected with optical fibers within an enclosure or the like. In an embodiment, the fiber optic receptacle includes an adapter sleeve that is biased toward a first end of the receptacle housing through which a fiber optic plug is inserted in order to maintain physical contact between front faces of the plug ferrule and the receptacle ferrule without requiring that the fiber optic connector of the fiber optic plug be latched to the adapter sleeve, thereby increasing the float between the respective ferrules. According to an embodiment, a fiber optic plug and fiber optic receptacle assembly is provided in which one of the fiber optic plug and the fiber optic receptacle includes an alignment stop and the other one of the fiber optic plug and the fiber optic receptacle includes an alignment feature and a stop feature to ensure alignment of the fiber optic plug and the fiber optic receptacle and to limit insertion, i.e., to prevent overinsertion, of the fiber optic plug within the fiber optic receptacle. According to a further embodiment, a universal fiber optic receptacle is provided in which an internal cavity defined by the receptacle housing and the associated adapter retainer is sized to receive any adapter sleeve, such as, for example, adapter sleeves configured to receive a plurality of connector types including MTP, MTRJ, SC-DC, SC, DC, Unicam(trademark), LC, and the like.
In an embodiment, a fiber optic receptacle is provided that includes a receptacle housing defining an internal cavity opening through opposed first end and second end. The fiber optic receptacle also includes an adapter sleeve disposed within the internal cavity defined by the receptacle housing. The adapter sleeve defines a lengthwise extending passage opening through opposed first end and second end for receiving and aligning the plug ferrule and the receptacle ferrule. In this embodiment, the fiber optic receptacle also includes a bias member disposed within the receptacle housing. The bias member operably engages the adapter sleeve and urges the adapter sleeve toward the first end of the receptacle housing. By urging the adapter sleeve toward the first end of the receptacle housing, the front faces of the plug ferrule and the receptacle ferrule are maintained in contact without having to latch the plug ferrule of the fiber optic plug to the adapter sleeve. As such, physical contact can be maintained between the front faces of the plug ferrule and the receptacle ferrule while permitting the ferrules to float.
In an embodiment, the bias member includes at least one spring disposed between the second end of the receptacle housing and the adapter sleeve. The receptacle housing of this embodiment can also include at least one post extending in a lengthwise direction from the second end. As such, each spring can be mounted upon a respective post.
The adapter sleeve preferably includes a sleeve member that extends lengthwise between opposed first end and second end. According to an embodiment, the second end of the sleeve member includes means for mechanically engaging a receptacle ferrule, such as, for example, a pair of latches. However, the first end of the sleeve member is preferably free of latches with the plug ferrule being held within the first end of the adapter sleeve by the spring loading of the adapter sleeve. The adapter sleeve can also include a pair of wings extending from opposite sides of the sleeve member. The pair of wings are engaged by the bias member to urge the adapter sleeve toward the first end of the receptacle housing.
The fiber optic receptacle can also include an adapter retainer connected to the receptacle housing proximate the first end thereof. The adapter retainer engages the adapter sleeve so as to retain the adapter sleeve within the receptacle housing.
In another embodiment, a fiber optic plug and fiber optic receptacle assembly is provided that facilitates the alignment of the fiber optic plug and the fiber optic receptacle and that limits the insertion of the fiber optic plug into the fiber optic receptacle, thereby preventing overinsertion. According to this embodiment, a fiber optic plug includes a plug body and a fiber optic connector disposed within the plug body. The fiber optic connector, in turn, includes a connector housing and a plug ferrule that is partially disposed within the connector housing. For mating with the fiber optic plug, the fiber optic receptacle includes a receptacle housing defining an internal cavity opening through both the opposed first end and second end and an adapter sleeve disposed within the internal cavity. The adapter sleeve defines a lengthwise extending passage for receiving a portion of the plug ferrule of the fiber optic plug. According to this embodiment, one of the fiber optic plug and the fiber optic receptacle includes an alignment stop, while the other one of the fiber optic plug and the fiber optic receptacle includes an alignment feature and a stop feature. The alignment stop engages the alignment feature to ensure alignment of the fiber optic plug and the fiber optic receptacle. In addition, the alignment stop is also adapted to contact the stop feature to thereby limit insertion of the fiber optic plug within the fiber optic receptacle. As such, the fiber optic plug and fiber optic receptacle assembly prevents overinsertion of the fiber optic plug into the fiber optic receptacle.
According to another embodiment, the fiber optic receptacle includes the alignment stop that is disposed in a fixed position within the receptacle housing. Correspondingly, the fiber optic plug of this embodiment includes the alignment feature and the stop feature. Thus, the alignment stop of the fiber optic receptacle can engage the alignment feature of the fiber optic plug to ensure alignment of the fiber optic plug and the fiber optic receptacle. In addition, the alignment stop of the fiber optic receptacle can contact the stop feature of the fiber optic plug to limit insertion of the fiber optic plug within the fiber optic receptacle.
The alignment stop can include a pin and the alignment feature can include a groove with a closed end for engaging a distal end of the pin in order to serve as the stop feature. In the embodiment that includes the pin, the pin has a predetermined length and extends alongside at least a portion of the adapter sleeve from a proximate end connected to the second end of the receptacle housing to the opposed distal end. The plug body of the fiber optic plug of this embodiment defines the groove for receiving the pin. Both the pin and the corresponding groove preferably extend in a lengthwise direction. In this regard, the plug body typically includes a first end adapted to be inserted into the fiber optic receptacle. As such, the groove defined by the plug body extends from an open end proximate the first end of the plug body to an opposed closed end that serves as the stop feature. Regardless of which component includes the alignment stop and the corresponding alignment feature and stop feature, the alignment stop facilitates the alignment of the fiber optic plug and the fiber optic receptacle and prevents overinsertion of the fiber optic plug into the fiber optic receptacle that could otherwise damage the fiber optic plug and the fiber optic receptacle.
According to another embodiment, a universal fiber optic receptacle is provided. The universal fiber optic receptacle includes a receptacle housing extending lengthwise between opposed first end and second end and an adapter retainer connected to the receptacle housing proximate the first end thereof. The adapter retainer and the receptacle housing cooperate to define an internal cavity sized to receive any one of an adapter retainer sized to receive any adapter sleeve, such as, for example, adapter sleeves configured to receive a plurality of connector types including MTP, MTRJ, SC-DC, SC, DC, Unicam(trademark), LC, and the like. The universal fiber optic receptacle of this embodiment also includes an adapter sleeve disposed within the internal cavity defined by the adapter retainer and the receptacle housing, including, for example adapter sleeves configured to receive a plurality of connector types including MTP, MTRJ, SC-DC, SC, DC, Unicam(trademark), LC, and the like. The adapter sleeve defines the lengthwise extending passage opening through the opposed first and second ends for receiving and aligning the plug ferrule and the receptacle ferrule. In an embodiment, the adapter retainer is threadably connected to the receptacle housing such that the adapter retainer is capable of being disconnected from the receptacle housing in order to access the adapter sleeve, such as to clean the adapter sleeve or the receptacle ferrule or to remove the current adapter sleeve and to insert a different type of adapter sleeve into the universal fiber optic receptacle. The universal fiber optic receptacle can also include a seal disposed between the adapter retainer and the receptacle housing. As such, a common receptacle can be utilized for a wide variety of applications that utilize different types of connectors, thereby reducing the number of different types of receptacles that must be manufactured and maintained in inventory.